Ventilation is a physiologic process which supplies oxygen to the body and removes carbon dioxide, a gaseous waste product. Ventilation is provided by the rhythmic back and forth motion of air in the trachea, caused by the rhythmic contraction and relaxation of the diaphragm. In seriously ill or injured patients unable to breathe adequately on their own, ventilation can be assisted by inserting an endotracheal tube through the oral or nasal cavity of a patient, a process often referred to as endotracheal intubation. An endotracheal tube is a single or double-lumen catheter that is open at both ends. One end extends outside of the patient and is engaged with a mechanical ventilator for supplying a ventilation fluid. The other end extends between the vocal cords and into the trachea of the patient.
Proper placement of the endotracheal tube typically requires the use of a guide instrument, such as a laryngoscope or a video-laryngoscope, to provide a degree of visualization of the internal anatomy of the patient. The laryngoscope may include a curved blade-like structure that is inserted into the pharynx. The blade-like structure elevates the epiglottis to provide a view of the vocal cords and the glottis, and provides a pathway for the end of the endotracheal tube to be manually directed past the vocal cords, and into the trachea. A handle engaged with the blade extends outside the throat to facilitate manipulation by the medical professional. During the intubation procedure, the professional typically grasps the handle of the laryngoscope with one hand, and controls the position of the endotracheal tube with the other hand.
With the patient lying on his or her back, the laryngoscope is typically inserted into the mouth on the right side, and then moved to the left side to move the tongue out of the line of sight. The blade is then lifted in an upward and forward motion to elevate the epiglottis such that the line of sight to the glottis is achieved. During this intubation process, the presence of a second, and sometimes even a third, person is generally required in order to manipulate the patient's head and jaw into alignment to enable optimal visualization of the vocal cords, and to assist with insertion of the endotracheal tube. Since both the laryngoscope and the endotracheal tube must be inserted into a small space in the vicinity of the vocal cords, the intubation procedure typically requires a high degree of experience and care on the part of the intubation team in order to ensure proper visualization and placement of the endotracheal tube, and to avoid damage to the vocal cords and other anatomical structures during the process of inserting the tube. The placement procedure is sometimes further complicated by edema, large tongues, facial trauma, and is particularly difficult in patients with Malenpatti scores of 2-4.
Moreover, devices such as laryngoscopes require a lot of force and often lead to broken teeth, soft palate abrasions, and other complications. Although the video laryngoscope allows the user to visualize the vocal cords after physical manipulation of the epiglottis such devices are expensive.